The effect of feeding change on nutrients and minerals composition of goat's milk

The aim of this study was to analyse the effect of change of feeding realised by beginning of grazing on composition of goat milk at ecological farm RD Pod Skalkou, Tvrdosin from middle April to end of June in 150 goats in different parities. For indoor feeding meadow hay (ad libitum) with grain feed and protein concentrate was used. Outdoor feeding using pasture and the same feed mixture like in indoor feeding was realised (0.2 kg crimped oat + 0.3 kg mixture of barley and corn in ratio 2:1 and 0.1 kg protein concentrate). Goats were milked twice a day using machine milking system. In all milk samples basic nutrients - according to standard laboratory methods, gross energy using Leco AC500, and minerals using CotrAA (R) 700 were determined. Except fat, lactose, ash, all analysed parameters of goat milk were significantly (P<0.05 resp. P<0.01) affected by beginning of grazing. Concentration of Ca, P, Mg, Na and Mn was highest in goat milk fed only indoors, whereas concentration of Cu, Fe and Zn was highest on 7th day after start of grazing. Described changes of basic nutrients, gross energy and minerals of goat milk confirm significant effect of beginning of grazing on milk composition.